/usr/share/gnome-session/sessions/gnome-fallback.session is in gnome-session-fallback 3.2.1-0ubuntu8.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | [GNOME Session]
Name=GNOME fallback (Safe Mode)
RequiredComponents=gnome-panel;gnome-settings-daemon;
RequiredProviders=windowmanager;
DefaultProvider-windowmanager=metacity
DefaultProvider-notifications=notify-osd
DesktopName=GNOME
|